Field of the Disclosure
The present disclosure relates to an electronic device, and more particularly, to an electronic device having a force touch function.
Discussion of the Related Art
A touch screen device is a type of input device that allows a user to input information through a screen of a display device without an additional input device. The touch screen device is generally used as the input device for various kinds of products such as television, notebook computer and monitor as well as portable electronic devices such as electronic notebook, electronic book (e-book), PMP (Portable Multimedia Player), navigation, UMPC (Ultra Mobile PC), mobile phone, smart phone, smart watch, tablet PC (tablet Personal Computer), watch phone, and mobile communication terminal.
Generally, the touch screen device may be largely classified into a resistive type which senses a touch position in accordance with a change of resistance value, and a capacitive type which senses a touch position in accordance with a change of capacitance. Recently, the capacitive type has attracted great attention due to advantages of being simpler to manufacture and having good sensitivity.
With a recent developments of applications that require touch information for a force touch, a capacitive type electronic device having a force touch function for sensing a touch force has been developed and studied.
A related art force sensing panel is provided on a cover window to sense a touch force in accordance with a user's force touch. The related art force sensing panel includes an elastic member, and first and second electrodes confronting each other with the elastic member interposed in-between. In case of the force sensing panel, a capacitance formed between the first and second electrodes is changed in accordance with a shape change of the elastic member by a user's force touch on the cover window. Accordingly, a touch driving circuit connected with the force sensing panel sense a user's touch force based on the change of capacitance formed between the first and second electrodes.
If the related art force sensing panel is applied to a small-sized electronic device such as a smart watch, the electronic device may include a housing having a receiving space, a cover window for covering an upper side of the housing, a display module attached to the cover window, and the force sensing panel disposed between the display module and the housing.
However, since the related art electronic device has a single electrode structure having a small area, a high amount of minimum pressure is needed before touch force can be sensed due to a relatively-small amount of deformation change that occurs when there is a touch force in a vertical direction.